Distance between Vega de San Mateo, Spain and San Salvador, El Salvador

7721 km = 4797 miles

During our distance calculation we made two assumptions.
1) We assumed a spherical Earth as a close approximation of the true shape of the Earth (an oblate spheroid). The distance was
calculated as great-circle or orthodromic distance on the surface of a sphere.
2) For each city we chose a particular point inside the city as the "city centre" and calculated the distance
between these "city centres" using their coordinates. Real distances between other points inside or near these cities,
for example, between airports, will differ from our calculation.